Dental chair.



No. 684,844. Patented 0st. 22, |90I.

' M. c. mennen.

DENTAL CHAIR.

(Application filed Feb. 26, 1901.) y (No Model.) 2 S'heeis-Sheet I.

34 ggg 7 www", A

In: Nonms Pzrzns co. PHoYLITHoA, WASHINGTON, D. c.

No. 684,844. Patented Oct. 22, |90I.

M. c. manici-zn. DENTAL GHMR.

(Application Sled Feb. 26, 1901.) (No Model.) 2 Sheets-Sheet 2.

UNITED STATES PATENT OEEICE.

MONT C. MERKER, OF NEW' YORK, N. Y.

DENTAL CHAIR.

SPECIFICATION forming part f Letters Patent NO. 684,844, dated October22, 1901 Original application tiled November 9, 1 898, Serial N o.695,930. Divided and this application filed February 26, 1901. Serial To@ZZ whom t may con/cern:

Be it known that I, MONT C. MERKER,a resident of New York, in the countyof New York and State of New York, have invented certain new and usefulImprovements in Dental Chairs; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such asu-'illenable others skilled in the art to which it pertains to make and usethe same.

This application is a division of application Serial No. 695,930, filedNovember 9, 1898; and the invention relates to dental chairs, and hasfor its object to increase their economy of construction and efficiencyin action and the certainty, ease, and convenience of the operation ofvarious parts.

The invention consists in the construction I, herein described andpointed out.

In the accompanying drawings, Figure 1 is a partial side elevation ofthe chair. Fig. 2 is a partial plan of the chair, the upholstered seat,back, and head-rest, and head-rest support being omitted. Fig. 3 is aplan of the seat-frame cross-bar partly broken away. Fig. 4 is a sectionon line 4 4 of Fig. 5. Fig. 5 is a partial section on line 5 5 of Fig.2. Fig. 6 is a broken section on line 6 6 of Fig. 5. Fig. 7 is a brokensection on line 7 7 of Fig. 6. Fig. 8 is a cross-section oftheback-frame and its extension.

l Numeral 1 denotes the cross-bar of a chairseat frame, and 2 aseat-frame-supporting tube having a lining 3.

4 denotes a screw-plug to secure the bar and tube together,and 5 is aset-screw. The screwplug 4 has a flaring head 4X, bearing on the beveledwall of an opening in the bar, as shown.

The seat-frame comprises a rear section 6, secured to side sections 6Xby screws 7, said side sections being secured by screws S to a frontplate 9. The side sections, if preferred, can be made integral with theside members 10 of a main foot-rest frame. In and between said sidemembers 10 is pivotally supported at 1l a supplemental frame 12, thatcarries a platform 13.

14 denotes an inclined platform pivoted at 15 to the frame 12. Saidframe 12 is adapted to be turned on its pivots 11 and carry the (Nomodel.)

parts 13 and 14 to a higher plane, as indicated in Figs. 1 and 5, tcserve, respectively, as a seat and foot-rest for the use of a child.These devices may be employed whenever it is desirable for a child orsmall person to occupy the chair. The elevated seat holds a smallpatient at a convenient height for thc operator, and the correspondin gfoot-rest is at a suitable height for the use of such patient. In suchposition the platform 13 is inverted, so that a cane-seat 16, suitablyattached thereto, is properly disposed for use. The platform 14 when inthe elevated situation and turned on its pivots 15 and supported by astop or stops 16L is properly disposed to support. the feet of a childoccupying seat 16.

Each of the platforms 13 and 14 are preferably carpeted, as indicated at17. Y The platform 14 has a cross-bar 18, which in itslower situationrests upon an arched bar 19, secured to the side members 10 of the mainfoot-rest frame. Braces are denoted by 20 connecting the main foot-restframe and the foot of a rack, to be described,with the front plate 9.Armrests are denoted by 21, shown without upholstering except in Fig. 1.They are held and guided in vertical adjustment by rods 22, sliding insockets 23 in the seat-frame. In Fig. 4 a part 24 of the rest stands ona ledge formed on the upper part of the socket-containing extension ofthe seat-frame. This denotes an elevated situation of the arm-rest,whereby it is adapted for use with the elevated situation of the childsseat. To lower the rest, it is turned half-way around and the part 24lowered to stand on an offset 25 of the frame between theretaining-flanges 26. .This situation of the rest is shown in Figs. 1and 5.

The seat-frame is supported to turn on the trunnions at the ends of thecross-baril. It is locked in position by a pin 27, which engages any oneof the sockets 2S in a rack 29, secured to the front plate 9 of theseat-frame. This pin is withdrawn from the rack 20 to permit theadjustment of the seat about the cross-bartrunnions by means of .a rod30, having a projection 31 situated in a recess 32 in the pin. The pin27 is normally held to its duty by a spring 36 on the rod 30.

The back-frame 37is supported to turn upon trunnions 38, fixed to theseat-frame. It has ICO a sliding extension 39, secured in place by aset-screw having a handle 4:0. The pivoted upholstered back 4l has apaw142 pivoted thereto and engaging the teeth of a rack 43 on thesliding extension 39, (see Figs. 5 and 1,) whereby said upholstered backmay `be held at any angle to which it may be adjusted. The back ispivoted at ory near its upper end in any usual ordesired manner. TheeXtension 39 is adjustable and slides between the side members of theback-f rame and carries the pivoted upholstered back. The said extensionis fixed by a set-screw having a handle 40, said screw passing through apart 40 of the back-frame and screwing into the extension. The extension39 has grooves between ribs. The outer ribs (indicated by 39` areinterrupted adjacent the screw, having a head 40, to provide that afastening-plate 40X may bear on the ribs of the back-frame situatedinside the grooves, whereby the extension 39 may be fixed to theback-frame, as indicated iu Fig. 8.

44 denotes a curved extension of the backframe, which has a rib 45, towhich is secured asteel strap or bar 4G, which extends laterally beyondthe rib on each side, as shown in Fig.6.

47 denotes the two members of a clampingyoke, and 4S are hooks carriedby the yoke members and engaging the under or outer faces of the bar 4G,as shown in Fig. U.

49 is a seat-frame extension situated between the yoke members and on alevel below the seat-frame arms that carry the trunnions of thechair-back frame. The function of the seat-frame extension is to supportbackframe-clainping devices operating to fix at will said back-framewhen adj usted about the trunnions. 50 is a pin screwed into said frameextension, upon which screw the yoke moves freely.

5l is a cam which can be made to bear upon the contiguous face of thebar 46 and coact with the hooks 4S of the yoke to solidly and quicklygrip said bar and tix the back in any desired adjustment. The cam isprovided with an operating or clamping lever 52, having an angularportion 53, which closely fits an angular opening in the same. The rodto it its bearings is reduced in size at its end beside the cam. Thelever 52 is normally pressed by a spring 54 (see Fig. 1) to operate theclamp, and the chair-back cooperates by gravity when it is situated backof a vertical central line through the cam. Said spring 54 has in thepresent instance a turned-up end 54"". (Indicated by full lines in Fig.l and broken lines in Fig. 2.) As indicated in the latter figure, it maybe secured to the seatframe by a bolt 549. Backward pressure by theoccupant also tightens the clamp, the action of which is instantaneous,without jar, and noiseless. It also permits a large are of movement andholds the back firmly, even when the latter is lowered to a horizontalplane or lower.

The particular form of the part herein styled a yoke is unimportant,provided it is adapted to coperate with an opposing part, such as thecam, to grip the bar between them. The bar-faces acted on by thesegripping devices are continuously smooth surfaces, except for thedepression MX, to receive a small projection 5l on the cam, it being theobject of this part of my improvement to facilitate the exact adjustmentand locking ot' the backframe at any and every desired angle within thesegment bounded by the curved bar. The projection 5l is not essential inall cases, but may be used to insure against slip.

VAnother ad vantage of the devices for locking the back-frame is thatwhen the frame is adjusted it need not be carried beyond the desiredpoint and returned to it in order to engage a pawl with a rack-tooth, asheretofore, the improved clamp being operative at every point of thecurved bar. It is obvious that the back, seat, and platform frames canbe tilted together, as indicated by dotted lines in Fig. l, and that theback-frame can beindependently tilted or adjusted.

The supplemental frame carrying both a reversible part adapted to serveeither for a platform or a seat and a supplemental part adapted to serveas a childs foot-rest is an economical and easily-manipulated structure.

The reversible arm-rests are important in a chair adapted forlarge andsmall occupants.

Other advantages will appear in practical use, and the novel features ofconstruction will be more particularly pointed out herein.

Having thus described my invention, what l claim as new, and desire tosecure by Letters Patent, is-

'1. In a dental chair, the pivotally-supported back-frame having adownward extension provided with a curved bar, a yoke embracing saidbar, a seat-frame extension, and means supported in said frame extensionoperating on said curved bar for forcing said yoke against the bar, allsubstantially as set forth, whereby the back-frame may be adjusted andthe seat and back frames locked together at any point of the bar.

2. In a dental chair, the pivotally-supported back-frame having adownward extension provided with a curved bar having free side edges anda lengthwise continuously-curved surface, a yoke embracing said bar onits rear side, a seat-frame extension, and means supported in said frameextension operating on the front surface of said curved bar for forcingsaid yoke against the rear surface of the bar, all substantially as setforth, whereby the back-frame may be adjusted and the seat and backframes may be locked together at any point of the bar.

3. In a dental chair, the pivotally-supportd ed back-frame having adownward extension provided with a curved bar, a yoke embracing saidbar, a seat-frame extension, and means supported in said frame extensionoperating IOO IIO

on said curved bar for forcing said yoke against the bar, said meanscomprising the cam and handle.

4. In a dental chair, the pivotally-supported back-frame havingadownward extension provided with a curved bar, a yoke embracing saidbar, a seat-frame extension, and means supported in said frame extensionoperating on said curved bar for forcing said yoke against the bar, saidmeans comprising the cam and handle, and a spring to hold the cam inoperative situation for forcing said yoke against the bar.

5. In a dental chair, an adjustable arm-rest combined with a seat-framehaving two distinct arm-rest supports situated at different elevationscorresponding to situations of the rest at two elevations.

6. In a dental chair, a reversible arm-rest combined with a seat-framehaving distinct arm-rest supports situated at different elevationscorresponding to opposite situations of the reversible rest, said resthaving a guiding-post entering the frame and a supporting arm or postresting on the frame.

7. In a dental chair, a reversible arm-rest combined with a seat-framehaving two distinct armrest supports situated at different elevationscorresponding to situations of the rest at two elevations, said supportsconsisting of a ledge on the exterior of the seat-frame extension andthe frame-oset 6X.

8. In a dental chair, the seat-frame, the main foot-rest frame, thesupplemental frame pivoted in said first-named frame and having in it afoot-platform provided on its under side with a seat, and having also asupplemental pivoted table filling the space between the side bars ofthe main foot-rest frame, and a stop bearing on said table atapproximately its mid-length and supporting it in its elevated situationwhen turned on its pivots, all substantially as described,whereby saidplatform and table may be used as a childs seat and foot-restrespectively.

9. In a dental chair, the seat-frame, the main foot-rest frame, thesupplemental frame pivoted in said first-named frame and having in it afoot-platform provided on its under side with a seat, and having also asupplemental pivoted table filling the space between the side bars ofthe main foot-rest frame, and a stop bearing on said table atapproximately its mid-length and supporting it in its elevated situationwhen turned on its pivots and the arched bar supported Qn the mainfootrest frame and bearing on the under side of the table in its lowersituation.

10. In a dental chair, the tilting seat-frame, the cross-bar having aforward extension provided with a recess, the recessed pin movablehorizont-ally in said bar-extension recess, the rod journaled in saidextension and provided with a projection situated in the pin-recess, anda rack carried by the seat-frame whereby the latter when adjusted can befixed, said rod being adapted to move the pin by rotation of the rod.

1l. In a dental chair, the cross-bar having a central opening, theseat-supporting tube 2, the nut seated in said opening and screwing intosaid tube, whereby the tube is fixed to the cross-bar and its upper endclosed. Y

In testimony whereof I have signed this speciiication in the presence oftwo subscribing witnesses.

MONT C. MERKER. Witnesses:

G. W. BALLocH, BENJ. R. CATLIN.

